System and method for redistribution of the flow of fuel under faulted conditions in a fuel cell system

Abstract

A system and method for redistribution of the flow of fuel under faulted conditions in a fuel cell system is disclosed. The fuel cell system includes a fuel cell stack; a fuel tank for storing fuel; fuel injectors that sequentially supply fuel from the fuel tank to the fuel cell stack; and a controller for determining whether a fault condition exists in one of the fuel injectors. If a fault condition exists in the first injector, the controller is capable of redistributing the flow of fuel from a first injector to a second injector.

What is claimed is: 
     
       1. A fuel cell system, comprising:
 a fuel cell stack; 
 a fuel tank for storing fuel; 
 a plurality of fuel injectors that sequentially supply fuel from said fuel tank to said fuel cell stack; and 
 a controller for determining whether a fault condition exists in one of said plurality of fuel injectors, said controller configured for redistributing the flow of fuel from a first injector to a second injector when the fault condition exists in said first injector. 
 
     
     
       2. A system as set forth in  claim 1 , wherein said fault condition comprises one of a normal condition, an open circuit condition, a short to power condition, and a short to ground condition. 
     
     
       3. A system as set forth in  claim 2 , wherein said controller determines that a commanded hydrogen flow of said first injector is equal to zero when either the open circuit condition or the short to power condition exists. 
     
     
       4. A system as set forth in  claim 2 , wherein said controller determines that a commanded flow of fuel from said first injector is equal to a maximum flow of fuel per injector when the short to ground condition exists. 
     
     
       5. A system as set forth in  claim 2 , wherein said controller determines that a commanded flow of fuel of said first injector is equal to a minimum between a maximum flow per injector and a total desired flow of fuel of said fuel cell system when the normal condition exists. 
     
     
       6. A system as set forth in  claim 1 , wherein said controller being capable of redistributing the flow of fuel from said first injector by determining a difference between a commanded flow of fuel of said first injector and a total desired flow of fuel of said fuel cell system. 
     
     
       7. A system as set forth in  claim 6 , wherein said controller determines whether said second injector is in the normal condition, and determining a minimum of the difference between the commanded flow of fuel of said first injector and a maximum flow of fuel per injector for said second injector when the normal condition exists. 
     
     
       8. A system as set forth in  claim 1 , wherein said second injector is a next injector in the sequence for providing fuel from said fuel tank to said fuel cell stack. 
     
     
       9. A system as set forth in  claim 1 , wherein said fuel comprises H 2 , and wherein H 2  is supplied to an anode side of said fuel cell stack. 
     
     
       10. A method for redistribution of the flow of fuel under faulted conditions in a fuel cell system, comprising the steps of:
 determining whether a fault condition exists in a first injector of a plurality of injectors of said fuel cell system, and 
 redistributing the flow of fuel from the one of said plurality of injectors to a second injector when the fault condition exists in said first injector. 
 
     
     
       11. A method as set forth in  claim 10 , further comprising the step of determining whether the fault condition is one of a normal condition, an open circuit condition, a short to power condition, and a short to ground condition. 
     
     
       12. A method as set forth in  claim 11 , further comprising the step of determining that a commanded hydrogen flow of said first injector is equal to zero when either the open circuit condition or the short to power condition exists. 
     
     
       13. A method as set forth in  claim 11 , further comprising the step of determining that a commanded flow of fuel from said first injector is equal to a maximum flow of fuel per injector when the short to ground condition exists. 
     
     
       14. A method as set forth in  claim 11 , further comprising the step of determining that a commanded flow of fuel of said first injector is equal to a minimum between a maximum flow per injector and a total desired flow of fuel of said fuel cell system when the normal condition exists. 
     
     
       15. A method as set forth in  claim 10 , further comprising the step of determining a difference between a commanded flow of fuel of said first injector and a total desired flow of fuel of said fuel cell system. 
     
     
       16. A method as set forth in  claim 15 , further comprising the step of determining whether said second injector is in the normal condition, and determining a minimum of the difference between the commanded flow of fuel of said first injector and a maximum flow of fuel per injector for said second injector when the normal condition exists. 
     
     
       17. A method as set forth in  claim 10 , wherein said second injector is a next injector in the sequence for providing fuel from said fuel tank to said fuel cell stack. 
     
     
       18. A method as set forth in  claim 10 , wherein said fuel comprises H 2 , and wherein H 2  is supplied to a anode side of said fuel cell stack.